1. Department of Gynecologic Oncology, National Cancer Center/Cancer HospitalChinese Academy of Medical Sciences & Peking Union Medical College Panjiayuan, Chaoyang District 100021 Beijing P.R. China
2. Department of Reproductive Center, Gynecology and ObstetricHenan Provincial People's Hospital of Zhengzhou University Jinshui Area 450003 Zhengzhou Henan P.R. China
3. Department of Obstetrics and GynecologySecond Affiliated Hospital of Sun Yat‐sen University Guangzhou China
4. Department of Obstetrics and GynecologyThird Affiliated Hospital of Guangzhou Medical University Guangzhou China